I know plenty of Uber (and normal taxis) drivers around the airport here who pick up a someone, then ask if they mind taking someone else. Because it is usually vans and business customers, they don't care and actually kind of like talking with other business guys who probably went or are going to the same seminar/conference etc. The driver will then load up whatever fits who are waiting for taxis or drivers and only report 1 person to the service. As this is hotel to airport to hotel, there are not many ways of uber, lyft etc detecting this unless someone rats them out. I asked a driver and obviously he responded with Uber screws me, I screw Uber.